Scottish actor James McAvoy refused to follow director Robert Redford's instructions to drop his accent while filming THE CONSPIRATOR - because it would have sent him "mad".The Atonement star appears in Redford's upcoming movie about the assassination of former U.S. President Abraham Lincoln.MCAvoy had to speak in a southern American drawl throughout the film and Redford was so concerned his Scottish voice would reappear he banned the actor from speaking in his native tongue even between takes. But MCAvoy refused to obey the order - and as soon as Redford left the set he would take the opportunity to relax his vocal cords. He says, "Robert wanted me to be American the entire time so whenever he was around I was. But as soon as he walked off set I was back being myself, which will probably make the accent terrible and everyone will pick holes in it. But I can't do it all the time - you would kinda go mad. When the camera stops running I need to take stuff back."